Inactivation of Escherichia coli Using Nanosecond Electric Fields and Nisin Nanoparticles: A Kinetics Study

Nisin is a recognized bacteriocin widely used in food processing, however, being ineffective against gram-negative bacteria and in complex food systems. As a result, the research of methods that have cell wall–permeabilizing activity is required. In this study, electroporation to trigger sensitization of gram-negative bacteria to nisin-loaded pectin nanoparticles was used. As a model microorganism, bioluminescent strain of E. coli was introduced. Inactivation kinetics using nanosecond pulsed electric fields (PEFs) and nisin nanoparticles have been studied in a broad range (100–900 ns, 10–30 kV/cm) of pulse parameters. As a reference, the microsecond range protocols (100 μs × 8) have been applied. It was determined that the 20–30 kV/cm electric field with pulse duration ranging from 500 to 900 ns was sufficient to cause significant permeabilization of E. coli to trigger a synergistic response with the nisin treatment. The kinetics of the inactivation was studied with a time resolution of 2.5 min, which provided experimental evidence that the efficacy of nisin-based treatment can be effectively controlled in time using PEF. The results and the proposed methodology for rapid detection of bacteria inactivation rate based on bioluminescence may be useful in the development and optimization of protocols for PEF-based treatments

Synergistic Interferon-Alpha-Based Combinations for Treatment of SARS-CoV-2 and Other Viral Infections

Background: There is an urgent need for new antivirals with powerful therapeutic potential and tolerable side effects. Methods: Here, we tested the antiviral properties of interferons (IFNs), alone and with other drugs in vitro. Results: While IFNs alone were insufficient to completely abolish replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), IFNα, in combination with remdesivir, EIDD-2801, camostat, cycloheximide, or convalescent serum, proved to be more effective. Transcriptome and metabolomic analyses revealed that the IFNα–remdesivir combination suppressed SARS-CoV-2-mediated changes in Calu-3 cells and lung organoids, although it altered the homeostasis of uninfected cells and organoids. We also demonstrated that IFNα combinations with sofosbuvir, telaprevir, NITD008, ribavirin, pimodivir, or lamivudine were effective against HCV, HEV, FLuAV, or HIV at lower concentrations, compared to monotherapies. Conclusions: Altogether, our results indicated that IFNα can be combined with drugs that affect viral RNA transcription, protein synthesis, and processing to make synergistic combinations that can be attractive targets for further pre-clinical and clinical development against emerging and re-emerging viral infections

The transparency of political parties and campaign financing in the Baltic states

Demokratinėse valstybėse politinės partijos atlieka tarpininko vaidmenį tarp visuomenės ir valdžios, kadangi visuotinių, lygių, slaptų ir reguliarių rinkimų metu piliečiai išrenka savo atstovus, kurie išreiškia jų interesus valdžioje. Politinis finansavimas partijoms yra būtinas, kad jos galėtų vykdyti visas savo funkcijas – dalyvautų rinkimuose, rungtųsi su oponentais rinkiminės kampanijos metu, galėtų sumokėti administracines partijos išlaidas. Todėl politinių partijų finansavimas yra kiekvienos demokratinės valstybės problema, nes į rinkiminius fondus patenkačios lėšos nevisuomet gali būti teisėtos ir skaidrios. Politinio finansavimo skaidrumas yra vienas iš demokratizacijos proceso aspektų, o Baltijos šalyse demokratinis valdymas trunka dar tik antrąją dešimtį, dėl to politinio finansavimo skaidrumas šiose valstybėse yra vis dar evoliucijonuojantis, kadangi kaip naujos demokratijos, jos dar negalėjo sukurti idealios įstatymų, reguliuojančių politinio finansavimo skaidrumą, bazės. Šiame darbe analizuojama Lietuvos, Latvijos ir Estijos politinių partijų ir kampanijų finansavimą reguliuojanti sistema, apžvelgiami šių valstybių įstatymai ir institucijos, reguliuojančios įstatymų veiksmingumą. Pirmojoje – teorinėje darbo dalyje analizuojami politinį finansavimą tyrinėjusių mokslininkų darbai ir analizė parodė, kad politinio finansavimo skaidrumas demokratijoje yra būtinas. Norint užtikrinti politinio finansavimo skaidrumą, reikalinga: aukų ribojimas, valstybinis finansavimas, rinkiminės kampanijos išlaidų ribojimas, finansinių ataskaitų viešumas ir institucijos, nešališkai prižiūrinčios politinio finansavimo reguliavimo sistemą. Antrojoje darbo dalyje analizuojamos Baltijos valstybių politinį finansavimą reguliuojančios sistemos – įstatymų bazės ir institucijos, prižiūrinčios įstatymų laikymąsi. Trečiojoje darbo dalyje naudojant lyginamosios analizės metodą lyginamos Lietuvos, Latvijos ir Estijos politinių partijų ir kampanijų finansavimo aspektai – palyginami aukų limitai, valstybės parama partijoms, rinkiminės kampanijos išlaidų ir laiko ribojimai, partijos finansinių ataskaitų viešumas ir institucijos, reguliuojančios politinio finansavimo skaidrumą. Darbo pabaigoje pateikiamos rekomendacijos ir išvados, kokios yra politinių partijų ir kampanijų finansavimo skaidrumą reguliuojančių įstatymų spragos Baltijos šalyse.Strong political parties are necessary in democracy, especially in the emerging countries. Parties need funding that they could survive, spread their political purpose and compete in the campaigns of the political elections. But the sources of the political funding and political money are very difficult thing, especially in the emerging democracies. There is no common opinion, how parties should be founding, or how all donations and public disclosure should be regulated. Nontransparent political financing is democracy’s illness, because the main democratic idea that all people are equal and one man is one voting is broken. The transparency of political parties and campaign financing are analyzed in this paper. Estonia, Latvia and Lithuania are new democracies; their democracy has not been functioning for even two decades. This paper analyzes if Baltic countries have political parties and campaign funding regulation and are there any instruments which regulate the transparency of political funding.Vytauto Didžiojo universiteta

Influence of the members of ras/pka signal transduction pathway on the yeast Saccharomyces cerevisiae cell death induced by natural acidification of the medium

Constantly changing environment is the major factor controlling the growth and development of the microorganisms. For quick generation of the cell response, information about changes in the cell environment is rapidly transmitted to the inner molecules of the cell. During the course of evolution the cells have developed signaling systems that are able to combine extracellular signals with the inner processes, as transcription, translation etc. One of the universal signaling systems is Ras/PKA signal transduction pathway. This system helps cells recognize the nutrient sources present in the growth medium.Environmental pH is one of the main factors influencing the growth, physiology and differentiation of yeast. In Saccharomyces cerevisiae, response to pH is determined by the RIM101 pathway. Recently, it was shown, that Ras/PKA signal transduction pathway regulates cell aging as response to environmental pH. Many aging and apoptosis features are conserved between yeast and multicellular microorganisms, and this makes them perfect model organisms. Yeasts are also suitable also for acidosis related disease studies. Evaluation of the cell growth and medium acidification of isogenic strains containing mutation in the members of Ras/PKA signal transduction pathway was performed. Mutations in these genes cause changes in metabolic activity of the cell.Members of the Ras/PKA signal transduction pathway participate in regulation of cell viability and lifespan during the natural gradual acidification of the medium and under acidic stress conditions. In this process RAS genes are acting as negative regulators. PDE1 gene is also negative regulator of the cell viability in these conditions. It was determined, that buffering of the medium increases lifespan significantly. Analysis of the cell death type showed that hyperactivation of the Ras/PKA signal transduction pathway caused by Ras2Val19 mutation induces apoptosis in yeast cells. Vice versa, downregulation of the pathway by deletion of RAS1 and RAS2 genes act as necrosis inducer. Activity of the phosphodiesterase 2 is related to the termination of the apoptosis in yeast cells and inactivation of the both phosphodiesterase genes induces necrosis in yeast cells. Buffering of the medium causes decreased cell mortality with apoptosis related markers. It was proved; that members of Ras/PKA signal transduction pathway regulate cell metabolism, viability, aging and death type during natural acidification of the environment and under acidic stress conditions

Draft genome sequence dataset of Latilactobacillus curvatus PN39MY isolated from fermented vegetables

Here we report the draft genome sequence of the Latilactobacillus curvatus PN39MY strain. The strain was isolated from Lithuanian traditionally (homemade) fermented cucumber. The genome consisted of 83 contigs with a total size of 1,899,018 bp, an N50 of 40562 and a GC% of 42.1. After sequence trimming, 83 contigs were annotated and 1910 genes were coding sequences. The average nucleotide identity (ANI) between PN39MY and Latilactobacillus curvatus_ZJUNIT8 was 99.45% identifying the strain as Latilactobacillus curvatus. No genes related to antimicrobial resistance or virulence factors were found. The data presented here can be used in comparative genomics to identify antimicrobial resistant genes, plasmids and/or virulence factors that may be present in related Latilactobacillus species. The draft genome sequence data was deposited at NCBI under Bioproject with the accession number PRJNA941180

Effect of biosynthesized silver nanoparticles on the growth of the green microalga haematococcus pluvialis and astaxanthin synthesis

Silver nanoparticles (AgNPs) are widely known for their antimicrobial activity in various systems from microorganisms to cell cultures. However, the data on their effects on microalgae are very limited. Unicellular green algae Haematococcus pluvialis is known for its ability to accumulate large amounts of astaxanthin under stress conditions. Therefore, it can be used as a suitable model system to test the influence of AgNPs on stress induction in unicellular algae, with visible phenotypic effects, such as astaxanthin synthesis and cell morphology. This study tested different AgNP concentrations (0–8 mg/L) effects on different growth stages (red and green) of H. pluvialis culture. Effects on cell morphology, culture productivity, and astaxanthin synthesis were evaluated. Data showed that the addition of high concentrations of AgNPs to the growing culture had a significant negative impact on culture productivity. Green-stage (HpG) cultures productivity was reduced by up to 85% by increasing AgNPs concentration to 8 mg/L while the impact on red-stage (HpR) culture was lower. Astaxanthin concentration measurements showed that AgNPs do not have any effect on astaxanthin concentration in HpG culture and caused decreased astaxanthin production rate in HpR culture. HpG culture astaxanthin concentration stayed constant at ~0.43% dry weight, while HpR culture astaxanthin concentration was significantly reduced from 1.89% to 0.60% dry weight by increasing AgNP concentration. AgNPs in the media lead to significant changes in cell morphology in both HpG and HpR cultures. Cell deformations and disrupted cytokinesis, as well as AgNPs and induced sexual reproduction, were observed

Phosphate Solubilizing Microorganism Bacillus sp. MVY-004 and Its Significance for Biomineral Fertilizers’ Development in Agrobiotechnology

In this study, a phosphate solubilizing microorganism was isolated from the soil of an agricultural field in Lithuania. Based on 16S rRNA gene sequence analysis, the strain was identified as Bacillus sp. and submitted to the NCBI database, Sector of Applied Bio-catalysis, University Institute of Biotechnology, Vilnius, Lithuania and allocated the accession number KY882273. The Bacillus sp. was assigned with the number MVY-004. The culture nutrient medium and growth conditions were optimized: molasses was used as a carbon source; yeast extract powder was used as an organic source; NH4H2PO4 was used as a nitrogen source; the culture growth temperature was 30 ± 0.5 °C; the initial value of pH was 7.0 ± 0.5; the partial pressure of oxygen (pO2) was 60 ± 2.0; the mixer revolutions per minute (RPM) were 25–850, and the incubation and the fermentation time was 48–50 h. Analysis using Liquid Chromatography Time-of-Flight Mass Spectrometry (LC-TOF/MS) results showed that Bacillus sp. MVY-004 produced organic acids such as citric, succinic, 2-ketogluconic, gluconic, malic, lactic, and oxalic acids. Furthermore, the experiment showed that Bacillus sp. MVY-004 can also produce the following phytohormones: indole-3-acetic (IAA), jasmonic (JA), and gibberellic (GA3) acids. In the climate chamber, the experiment was performed using mineral fertilizer (NPS-12:40:10 80 Kg ha−1) and mineral fertilizers in combination with Bacillus sp. MVY-004 cells (NPS-12:40:10 80 Kg ha−1 + Bacillus sp. MVY-004) in loamy soil. Analysis was performed in three climate conditions: normal (T = 20 °C; relative humidity 60%); hot and dry (T = 30 °C; relative humidity 30%); hot and humid (T = 30 °C; relative humidity 80%)

Effects of pulsed electric fields on yeast with prions and the structure of amyloid fibrils

Prions are misfolded, self-replicating, and transmissible proteins capable of causing different conditions that affect the brain and nervous system in humans and animals. Yeasts are the perfect model to study prion formation, dissemination, and the structure of protein aggregates. Yeast prions are related to stress resistance, cell fitness, and viability. Applying a pulsed electric field (PEF) as a factor capable of disintegrating the amyloid aggregates arises from the fact that the amyloid aggregates form via noncovalent bonds and stabilize via electrostatic interactions. In this research, we applied 2–26 kV/cm PEF delivered in sequences of 5 pulses of 1 ms duration to the Saccharomyces cerevisiae cell without prions and containing strong and weak variants of the [PSI+] prion (prion form of Sup35 translation termination factor). We determined that prions significantly increase cell survivability and resistance to PEF treatment. The application of PEF to the purified Sup35NM fibrils showed that the electric field causes significant reductions in the length of fibrils and the full disintegration of fibrils to Sup35 oligomers can be achieved in higher fields